Spring structures



April 16, 1957 J. B. CRAHAN 2,788,844

SPRING STRUCTURES Filed March 28, 1955 INVENTOR JACK B. CRAHAN TORNEYS United StatcsPatent F SPRING STRUCTURES Jack B. Crahan, Wayzata, Minn., assignor to Northome Furniture Industries Inc., Dubuque, Iowa, :1 corporation of Minnesota Application March 28, 1955, Serial No. 497,281

6 Claims. (Cl. 155-479) The herein disclosed invention relates to spring structures for seats for furniture vehicles, and the like, and particularly to relatively deep and soft spring structures where considerable movement occurs in the use of the seat.

An object of the invention resides in providing a spring structure in which back and forth and lateral movement of the upper portion of the spring structure with reference to the lower portion of the spring structure is greatly reduced.

Another object of the invention resides in providing motion restraining means extending from one end portion of the lowermost part of the spring structure to the opposite end portion of the uppermost part.

A still further object of the invention resides in utilizing one or more links for the motion restraining means.

Another object of the invention resides in attaching the links to the rearward portion of the lower part of the spring structure and to the forward portion of the upper part of the spring structure.

An object of the invention resides in arranging the links in diagonal relation to resist both back. and forth and lateral movement.

A still further object of the invention resides in providing a spring structure having a supporting frame'with C-shaped springs attached thereto and connected at their upper ends by tie bars and in securing thelinks to said frame at the rearward portion thereof and to the tie bars of the outermost springs at the forward portions thereof.

Other objects of the invention reside in the novel combination and arrangement of parts and in the details of construction hereinafter illustrated and/or described.

In the drawings:

Fig. 1 is a plan view of a spring structure an embodiment of the invention.

Fig. 2 is a side elevational view of the structure shown jnFig. 1.

' Fig. 3 is a view siinilar'to Fig. 2 and showing the spring compressed at the forward'portion thereof.

The "spring structure'shown'in the drawing consists of 'afrarne 19 having two longitudinally extending frame members 11 and 12. These frame members are in the form of channels and are spaced from one another and from the outermost portion of the spring structure as best shown in Fig. l. The said frame members have oifsets illustrating 13 at the ends of the same and which are adapted to be mounted on the chair or chassis of the vehicle where the spring is to be used and which bring the spring structure to the proper height. Secured to the frame members 11 and 12 by means of rivets 14 are two transverse frame members 15 and 16. The frame members 15 and 16 are disposed inwardly from the offsets 13 of the frame members 11 and 12 as best shown in Figs. 2 and 3.

Attached to the frame members 15 and 16 are a number of spring units 18, 19, 20, 21 and 22. These spring units are identical in construction and only the spring unit 18 will be described in detail. This spring unit consists of two leaf springs 24 and 25 which are C-shaped in form and which have upper and lower legs 26 and 27. The legs 27 are riveted to the transverse frame members 15 and 16 by means of rivets 28. Attached to the upper legs 26 of these springs are two tie bars 29 and 30. The said tie bars are secured to said springs by means of rivets 31 and 32 and the said tie bars are located adjacent the edges of the springs 24 and 25. The other units 19, 29, 21 and 22 are attached to the transverse frame members 15 and 16 in the same manner. These spring units are all spaced from one another and the spring units 18 and 22 are disposed at the ends of the transverse frame members.

To carry the upper part of the spring structureforward of the springs 25, the following construction is employed: The tie bars 29 and 39 are provided with ex-. tensions 33 which project outwardly beyond the rivets 32. Attached to these extensions by means of rivets 34 are plates 35 which are bent upwardly as shown in Fig. 2. A wire edging member 36 extends about the front and a portion of the sides of the spring structure. This edge member has a forward portion 41 and lateral portions 42 which lie in close proximity to the outer spring units 18 and 22 and to the forward ends of the plates 35. The forward portion 41 is attached to plates 35 by means of clips 37. The clips 37 are secured to the plates 35 by means of rivets 39. Similarly the lateral portions 42 are attached to the portions 26 of springs 25 by means of the rivets 32 which secure said springs to the tie bars 29. This edging member serves to retain the cushion in proper form and to strengthen and reinforce the spring structure at the forward portion thereof.

The edging member 36 serves to hold the'forward ends of the tie bars 2? and 30 from movement relative to one another and cause them to move in unison. The rearward portions of these tie bars are similarly held from lateral movement and caused to move in unison by-m'eans of a reinforcing member 46. This reinforcing member is secured to the tie bars 29 and 30 of the spring unit 22 and of the spring unit 18 by means'of rivets 47 which extend through said tie bars and reinforcing member. The other tie bars are attached to said reinforcing member by means of clips 48.

The invention proper consists of two links 43 and 44 which are attached to the longitudinal frame members 11 and 12 by means of rivets-45. The points of attachment are immediately forward of the transverse frame member 15. The links 43 and 44 extend upwardly and diagonally towards the inner tie bar 30 and are secured under the rivets 31 which hold the springs 25 attached to said tie bars. These links restrain appreciable forward movement of the top part of thespring structure when weight is placed upon the forward portion of the same as shown in Fig. 3. 1

The method of operation of the invention is obvious. When a load is placed upon the tie bars 29 and 30, the springs 24 and 25 partially collapse and the said tie bars lower. Without the links 43 and 44, the upper part of the spring structure would have a tendency to shift an appreciable distance in a forward and/or lateral direction, thus distorting the cushion and in a short time spoiling the shape and appearance of the same. With the links in position, such movement is restrained and only a slight movement of the upper part of the spring structure occurs such as illustrated in Fig. 3. At the same time the links being arranged in a diagonal direction, limit lateral movement of the upper part of the spring structure and thus cause the upper part thereof to move in an up and down direction.

The advantages of the invention are manifest. The

invention is exceedingly simple and may be added to existing spring structures without appreciable expense. The links employed operate to restrain both back and fortlrmovem ent and lateral movement of. the upper part of the springfstructure relative to the lower part thereof, thereby limiting the movement of the upper part of the js'pringstructure to substantially up and'down movement. The invention does not impair the flexibility or softness of thespring structure and at the same time does not give the person seated on the seat carried by the spring structure a sensation of lateral or back and forth movement.

Changes in the specific form of the invention, as herein described, may be made within the scope of what is .claimed without departing from the spirit of the invention. Having described'the invention, what is claimedas new and desired to be protected by Letters Patent is:

l. A spring structure comprising a supporting frame havingspaced longitudinal frame members and transverse frame members secured thereto, spaced upright spring units secured to said frame at the rear and forward portion thereof and comprising upright C-shaped leaf springs having upper'and lower legs, the lower legs thereof being attached to said transverse frame members, tie bars extending across and secured to the upper legs of said leaf springs, front and rear connecting members attached to the tie bars and connecting the tie bars together and links connected to said frame at the rearward portion thereof and to certain'of said units at the connections between 'thenpper'legs of the C springs and the tie bars of the 1 forward portions of said units.

2, A spring structure comprising a supporting frame having spaced longitudinal frame members and transverse frame'members secured thereto, spaced upright spring units secured to said frame at the rear and forward portions thereof and comprising upright C-shaped leaf springs having upper and lower legs, the lower legs thereof being attached to said transverse frame members, tie

bars extending across and secured to the upperlegs of said leaf springs, front and rear connecting members attached to the tie bars and connecting the tie bars to g'ether and a pair of links connected to said frame at the rearward portion thereof and to certain of said unitsat the connections between the upper legs of the C'springs and the tie bars of the forward portions of said units.

3. A spring structure comprising a supporting frame having spaced longitudinal frame members and transverse frame members secured thereto, spaced upright spring units'secured to said frame at the rear and forward portions thereof and comprising upright C-shaped leaf springs having upper and lower legs, the lower legs thereof being attached'to said transverse frame members, tie bars ex- .tendingacross and secured to the upper legs of said leaf springs, front and rear connecting members attached to the tie bars and connecting the tie bars together and a pair of longitudinal links secured at their rearward ends to said frame at the rearward portion thereof and inwardly of the outermost spring units, said links extending diagonally upwardly and outwardly and being secured at 4 their forward ends to the outer spring units at the upper and forward portions thereof. 7

4. A spring structure comprising a supporting frame having spaced longitudinal frame members and transverse frame members secured thereto, spaced upright spring units secured tosaid frame at the rear and forward portions thereof and comprising upright C-shaped leaf springs having upper and lower legs, the lower legs thereof being attached to said transverse frame members, tie bars ex tending across and secured to the upper portions of said leaf springs, front and rear connecting members attached to the tie bars and connecting the tie bars together and a pair of longitudinal links secured at their rearward ends to said longitudinal frame members at the location of the rear transverse frame'member and inwardly of the outermost spring units, said links extending diagonally upwardiy and outwardly and being secured at their forward ends to the outer spring units at theupper and forward portions thereof.

5. A spring structure comprising a supporting frame having spaced longitudinal frame members and transverse frame members secured thereto, spaced upright spring units secured to said frame at the rear and forward portions thereof and comprising upright C-shaped leaf springs having upper and lower legs, the lower legs thereof being attached to said transverse frame members, tie bars extending across and secured to the upper legs of said leaf springs, front and rear connecting members attached to the tie bars and connecting the tie bars together and a pair of longitudinal links secured at their rearward ends to said longitudinal frame members at the location of the rear transverse frame member and inwardly of the outermost spring units, said links extending diagonally upwardly and outwardly and being secured at their forward ends to the forward connecting member at the forward portion of the outer spring units.

6. A spring structure comprising a supporting frame having spaced longitudinal frame'members and transverse frame 'members secured thereto, spaced upright spring .units securedtosaid frame at the rear and forward portions thereof and comprising uprightC-shaped leaf springs having upper and 'lowerlegs, the lower legs thereof being attached to said transverse frame members, tie bars extending across and overlying the upper legs of said leaf springs, a pair of fiat flexible links secured to the rear-- most transverse frame member and extending diagonally upwardly and outwardly therefrom, their outer ends being disposed between one of said tie bars and the upper legs of theoutermost spring'units, and rivets extending jointly through said tie bars, links and spring legs and holding the parts secured together;

References Cited in the file of this patent UNITED STATES PATENTS 

